No offense to anyone, but DBZ would be one of the last anime that I would call action packed. In fact, I was surprised at how little fighting they actually do on a per episode basis. I remeraber brief segments of fighting sandwiched between long perioRAB of staring, panting, and protracted internal analysis of the opponent. I was annoyed by it's dependence on pan-and-scan to extend the length of the episodes.
One Piece, while many of the episodes are story driven, does have some of the best fight sequences in anime. I'd have to second Black Lagoon, as well, though it does address morality just as much as it features gun battles.